EP 1921611 A2 20080514 - Magnetic write head employing multiple magnetomotive force (MMF) sources
Title (en)
Magnetic write head employing multiple magnetomotive force (MMF) sources
Title (de)
Magnetischer Schreibkopf mit mehreren Quellen für magnetomotorische Kraft
Title (fr)
Tête d'écriture magnétique utilisant des sources multiples de force magnétomotrice (MMF)
Publication
Application
Priority
US 59841906 A 20061113
Abstract (en)
A write head for perpendicular magnetic recording having a write pole and first and second return poles. The write head can include a first magnetomotive force source for delivering a magnetomotive force to the first return pole and the write pole and a second magnetomotive force source for delivering magnetomotive force to the second return pole and the write pole. The first and second magnetomotive force sources can be operated independently of one another so that different relative amounts of magnetomotive force can be applied to the first and second return poles. A trailing magnetic shield can be connected with one of the return poles, such as the second return poles, and the variation in magnetomotive force can be used to increase the amount of flux flowing through the trailing shield when increased field gradient is desired (such as when writing a transistion), and to decrease the amount of flux through the trailing shield when decreased field gradient and increased write field are desired (such as when writing a long magnetic section on a magnetic medium).
IPC 8 full level
G11B 5/127 (2006.01); G11B 5/31 (2006.01)
CPC (source: EP US)
G11B 5/1278 (2013.01 - EP US); G11B 5/17 (2013.01 - EP US); G11B 5/3123 (2013.01 - EP US); G11B 5/3143 (2013.01 - EP US)
Designated contracting state (EPC)
DE FR GB
Designated extension state (EPC)
AL BA HR MK RS
DOCDB simple family (publication)
EP 1921611 A2 20080514; EP 1921611 A3 20081008; CN 101183530 A 20080521; JP 2008123666 A 20080529; US 2008112080 A1 20080515
DOCDB simple family (application)
EP 07252787 A 20070712; CN 200710186073 A 20071113; JP 2007293129 A 20071112; US 59841906 A 20061113